Geothermal energy collection system

Abstract

This invention provides a method of extracting geothermal energy, generally comprising the steps of: insertion of a thermal mass into a Heat Absorption Zone, absorbing heat in thermal mass, raising the thermal mass to a Heat Transfer Zone, and transferring the heat from the thermal mass. The acquired heat can be used to generate electricity or to drive an industrial process. The thermal mass can have internal chambers containing a liquid such as molten salt, and can also have structures facilitating heat exchange using a thermal exchange fluid, such as a gas or a glycol-based fluid. In some embodiments, two thermal masses are used as counterweights, reducing the energy consumed in bringing the heat in the thermal masses to the surface. In other embodiments, solid or molten salt can be directly supplied to a well shaft to acquire geothermal heat and returned to the surface in a closed loop system.

What is claimed is: 
     
       1. A method for transferring geothermal heat, comprising the steps of:
 preparing at least two thermal masses connected by a cable; 
 lowering a first thermal mass among the at least two thermal masses to a first heat absorption zone; 
 raising the first thermal mass to a first heat transfer zone while simultaneously lowering a second thermal mass among the at least two thermal masses to a second heat absorption zone; 
 transferring heat out of the first thermal mass; 
 raising the second thermal mass to a second heat transfer zone while simultaneously lowering the first thermal mass to the first heat absorption zone; and 
 transferring heat out of the second thermal mass, 
 wherein each of the first thermal mass and the second thermal mass further comprises internal piping configured to facilitate heat exchange between the first thermal mass or the second thermal mass and a thermal exchange fluid disposed in the internal piping. 
 
     
     
       2. The method of  claim 1 , in which the steps of transferring heat out of the first thermal mass or the second thermal mass comprises transferring the first thermal mass or the second thermal mass to a thermal reservoir. 
     
     
       3. The method of  claim 2  in which the heat transferred to the thermal reservoir is used to generate electricity. 
     
     
       4. The method of  claim 1 , in which at least one of the at least two thermal masses comprises a chamber for containing a thermal fluid; and
 the step of transferring heat out of the first thermal mass with a chamber or the second thermal mass with a chamber comprises transferring the thermal fluid contained in the first thermal mass or the second thermal mass out of the first thermal mass or the second thermal mass. 
 
     
     
       5. The method of  claim 4 , in which the step of transferring the heat out of the first thermal mass or second thermal mass additionally comprises transferring the thermal fluid into a thermal reservoir. 
     
     
       6. The method of  claim 4 , in which the thermal fluid comprises one or more of water, a molten salt selected from potassium calcium nitrate, sodium fluoride, and potassium nitrate. 
     
     
       7. The method of  claim 1 , wherein the internal piping of the first thermal mass is arranged in a coiled configuration. 
     
     
       8. The method of  claim 7 , wherein the coiled configuration comprises one or more of:
 a double helix; and 
 a helical heat exchange portion and a linear return portion. 
 
     
     
       9. The method of  claim 1 , wherein the internal piping of each thermal mass is arranged in a coiled configuration. 
     
     
       10. The method of  claim 9 , wherein each coiled configuration comprises one or more of:
 a double helix; and 
 a helical heat exchange portion and a linear return portion. 
 
     
     
       11. The method of  claim 1 , in which at least one of the at least two thermal masses comprises a heat exchanger; and
 the step of transferring the heat out of the first thermal mass or the second thermal mass comprises passing a transfer fluid through the heat exchanger. 
 
     
     
       12. The method of  claim 11 , in which the transfer fluid passing through the heat exchanger of the thermal mass also passes through a second heat exchanger in the heat transfer zone. 
     
     
       13. The method of  claim 11 , in which the transfer fluid comprises water. 
     
     
       14. The method of  claim 11 , in which the transfer fluid comprises a glycol-based fluid. 
     
     
       15. The method of  claim 11 , in which the step of transferring the heat out of the first thermal mass or the second thermal mass with a heat exchanger additionally comprises storing the transfer fluid that has passed through the heat exchanger in a thermal reservoir. 
     
     
       16. The method of  claim 15 , in which the transfer fluid is transferred into the thermal mass from a cool reservoir. 
     
     
       17. The method of  claim 11 , in which the transfer fluid comprises a molten salt. 
     
     
       18. The method of  claim 17 , in which the molten salt comprises potassium calcium nitrate. 
     
     
       19. The method of  claim 17 , in which the molten salt comprises potassium nitrate. 
     
     
       20. The method of  claim 17 , in which the molten salt comprises Sodium fluoride. 
     
     
       21. The method of  claim 1 , in which the first heat absorption zone and the second heat absorption zone are both in approximately the same location; and
 the first heat transfer zone and the second heat transfer zone are both in approximately the same location. 
 
     
     
       22. The method of  claim 21 , in which the first heat absorption zone and the second heat absorption zone are both at the bottom of a well shaft; and
 the first heat transfer zone and the second heat transfer zone are both near the top of the well shaft. 
 
     
     
       23. A method for extracting geothermal energy from the Earth, comprising the steps of:
 lowering a thermal mass comprising a quantity of salt into a geothermal heat absorption zone; 
 heating the quantity of salt; 
 raising the quantity of salt to a heat transfer zone; 
 transferring the quantity of salt into a thermal reservoir; and 
 monitoring one or more environmental conditions utilizing one or more sensors coupled to the thermal mass, the one or more sensors comprising:
 at least one accelerometer; 
 at least one temperature sensor including one or more of a platinum resistance thermometer and a dual metal thermostat; 
 at least one acoustic sensor; 
 at least one of optical sensors, infrared sensors, and fluorescence sensors; and 
 at least one pressure sensor. 
 
 
     
     
       24. The method of  claim 23 , in which the step of lowering a quantity of salt comprises moving the quantity of salt with a screw mechanism. 
     
     
       25. The method of  claim 23 , in which the quantity of salt is initially in solid form, and in which heating the quantity of salt comprises melting the salt. 
     
     
       26. The method of  claim 25 , in which the solid form of the salt is a powder. 
     
     
       27. A method for generating electricity, comprising the steps of:
 heating a thermal mass in a heat absorption zone; 
 raising the thermal mass to a heat transfer zone; 
 transferring the heat out of the thermal mass and into a thermal reservoir; 
 using the heat in the thermal reservoir to drive a turbine that generates electricity; and 
 wherein the thermal mass comprises a thermal exchange fluid, the thermal exchange fluid being selected from a group consisting of: 
 one or more molten salts selected from:
 sodium nitrite; 
 sodium nitrate; 
 sodium chloride; 
 potassium fluoride; and 
 potassium chloride; 
 
 a glycol-based fluid; 
 one or more metals; and 
 one or more gases selected from
 nitrogen; 
 argon; 
 helium; and 
 compressed carbon dioxide. 
 
 
     
     
       28. A method for generating electricity, comprising the steps of:
 lowering a quantity of salt into a geothermal heat absorption zone; 
 heating the quantity of salt; 
 raising the quantity of salt to a heat transfer zone; and 
 transferring the quantity of salt into a thermal reservoir using the heat from the salt in the thermal reservoir to drive a turbine that generates electricity.